A protective film is typically formed on a surface of a glass substrate of thin film transistor liquid crystal display (TFT LCD) in a TFT LCD production line, and therefore the first step in the process is usually removing the protective film from the surface of the glass substrate by a stripping apparatus and then transferring the glass substrate away from the stripping apparatus for a subsequent cleaning.
An operation process in a conventional stripping apparatus is shown in FIGS. 1A-1C. The conventional stripping apparatus comprises a film collector 1, vacuum suction roller 2, and nozzles 51, 52 and 53. A protective film 3 is formed on a glass substrate 4. The protective film 3 can be removed from the glass substrate 4 in a following manner. First, a transfer device 6 transfers the glass substrate 4 with the protective film 3 to pass under the vacuum suction roller 2 while the nozzle 51 blows the front end of the protective film 3 from the glass substrate 4 towards the vacuum suction roller 2, as shown in FIG. 1A. Then the protective film 3 is sucked onto the vacuum suction roller 2, as shown in FIG. 1B. With the help from nozzles 52 and 53, the protective film 3 is then transferred into the film collector 1 by the vacuum suction roller 2, as shown in FIG. 1C. During the above processes, the transfer speed of the glass substrate 4 is relatively fast, for example, in a range of about 0.1 m/s˜0.2 m/s. However, in some cases, the protective film 3 is not completely removed from the glass substrate 4 by either dangling on the nozzle 51, 52 or 53 or staying on the transfer device 6, thus blocking the normal transfer of the current glass substrate 4 or a next glass substrate in the production line, or in some cases, deflecting the glass substrate 4 from a normal track. This in turn can cause the damage to the glass substrate 4. Furthermore, when the protective film 3 fails to be removed from the glass substrate 4, the glass substrate 4 still moves forward in the production line until being detected by a film sensor in the next stage. At the time, the transfer device 6 stops the transfer of the glass substrate 4 and the production line halts.
The above design of the conventional stripping apparatus may increase the damage risk of the glass substrate since the glass substrate may be deflected from the normal track and fallen off the transfer device. Furthermore the stripping failure rate is also high due to the relatively fast transfer speed of the glass substrate. Since there is also lack of appropriate control means to secure the subsequent production after the stripping failure, the overall production yield suffers.